As a conventional die apparatus for use in powder compaction of metal, ceramics, or the like, an apparatus including a die having a cavity and upper and lower punches respectively inserted into the cavity from above and below of the cavity is used. In the die apparatus, the cavity of the die is filled with powder of metal, ceramics, or the like, and the powder is compacted by the punches inserted into the cavity from above and below of the die so as to compact the powder.
In this case, depending on the shape of the powder compact to be formed, the die may be divided into two or more. Each of the divided dies has cut surfaces extending along a moving direction of the punches, and is reciprocatingly movable in a direction of forming the cavity.
For example, if the die is divided into three, each of the dies is moved forward in the direction of the cavity from three directions, and each die comes into contact with the adjacent dies on the cut surfaces thereof so as to close the dies, thereby forming the cavity (see Patent Literature 1, for example).
In the apparatus described in Patent Literature 1, powder of metal, ceramics, or the like in the cavity filled from a powder supply apparatus disposed above the cavity is compacted by upper and lower punches into a powder compact, and thereafter, each die is moved backward so as to release the powder compact from the dies.